The new "use_va" module parameter (default: false) is used in vdpa_alloc_device() to inform the vDPA framework that the device supports VA.
vringh is initialized to use VA only when "use_va" is true and the user's mm has been bound. So, only when the bus supports user VA (e.g. vhost-vdpa). vdpasim_mm_work_fn work is used to attach the kthread to the user address space when the .bind_mm callback is invoked, and to detach it when the device is reset. Signed-off-by: Stefano Garzarella <[email protected]> --- drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 + drivers/vdpa/vdpa_sim/vdpa_sim.c | 104 ++++++++++++++++++++++++++++++- 2 files changed, 103 insertions(+), 2 deletions(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h index 07ef53ea375e..1b010e5c0445 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h @@ -55,6 +55,7 @@ struct vdpasim { struct vdpasim_virtqueue *vqs; struct kthread_worker *worker; struct kthread_work work; + struct mm_struct *mm_bound; struct vdpasim_dev_attr dev_attr; /* spinlock to synchronize virtqueue state */ spinlock_t lock; diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index 36a1d2e0a6ba..6e07cedef30c 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -36,10 +36,90 @@ module_param(max_iotlb_entries, int, 0444); MODULE_PARM_DESC(max_iotlb_entries, "Maximum number of iotlb entries for each address space. 0 means unlimited. (default: 2048)"); +static bool use_va; +module_param(use_va, bool, 0444); +MODULE_PARM_DESC(use_va, "Enable the device's ability to use VA"); + #define VDPASIM_QUEUE_ALIGN PAGE_SIZE #define VDPASIM_QUEUE_MAX 256 #define VDPASIM_VENDOR_ID 0 +struct vdpasim_mm_work { + struct kthread_work work; + struct task_struct *owner; + struct mm_struct *mm; + bool bind; + int ret; +}; + +static void vdpasim_mm_work_fn(struct kthread_work *work) +{ + struct vdpasim_mm_work *mm_work = + container_of(work, struct vdpasim_mm_work, work); + + mm_work->ret = 0; + + if (mm_work->bind) { + kthread_use_mm(mm_work->mm); +#if 0 + if (mm_work->owner) + mm_work->ret = cgroup_attach_task_all(mm_work->owner, + current); +#endif + } else { +#if 0 + //TODO: check it + cgroup_release(current); +#endif + kthread_unuse_mm(mm_work->mm); + } +} + +static void vdpasim_worker_queue_mm(struct vdpasim *vdpasim, + struct vdpasim_mm_work *mm_work) +{ + struct kthread_work *work = &mm_work->work; + + kthread_init_work(work, vdpasim_mm_work_fn); + kthread_queue_work(vdpasim->worker, work); + + spin_unlock(&vdpasim->lock); + kthread_flush_work(work); + spin_lock(&vdpasim->lock); +} + +static int vdpasim_worker_bind_mm(struct vdpasim *vdpasim, + struct mm_struct *new_mm, + struct task_struct *owner) +{ + struct vdpasim_mm_work mm_work; + + mm_work.owner = owner; + mm_work.mm = new_mm; + mm_work.bind = true; + + vdpasim_worker_queue_mm(vdpasim, &mm_work); + + if (!mm_work.ret) + vdpasim->mm_bound = new_mm; + + return mm_work.ret; +} + +static void vdpasim_worker_unbind_mm(struct vdpasim *vdpasim) +{ + struct vdpasim_mm_work mm_work; + + if (!vdpasim->mm_bound) + return; + + mm_work.mm = vdpasim->mm_bound; + mm_work.bind = false; + + vdpasim_worker_queue_mm(vdpasim, &mm_work); + + vdpasim->mm_bound = NULL; +} static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa) { return container_of(vdpa, struct vdpasim, vdpa); @@ -66,8 +146,10 @@ static void vdpasim_vq_notify(struct vringh *vring) static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx) { struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; + bool va_enabled = use_va && vdpasim->mm_bound; - vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false, false, + vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false, + va_enabled, (struct vring_desc *)(uintptr_t)vq->desc_addr, (struct vring_avail *) (uintptr_t)vq->driver_addr, @@ -96,6 +178,9 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim) { int i; + //TODO: should we cancel the works? + vdpasim_worker_unbind_mm(vdpasim); + spin_lock(&vdpasim->iommu_lock); for (i = 0; i < vdpasim->dev_attr.nvqs; i++) { @@ -275,7 +360,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops, dev_attr->ngroups, dev_attr->nas, - dev_attr->name, false); + dev_attr->name, use_va); if (IS_ERR(vdpasim)) { ret = PTR_ERR(vdpasim); goto err_alloc; @@ -657,6 +742,19 @@ static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid, return ret; } +static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct *mm, + struct task_struct *owner) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + int ret; + + spin_lock(&vdpasim->lock); + ret = vdpasim_worker_bind_mm(vdpasim, mm, owner); + spin_unlock(&vdpasim->lock); + + return ret; +} + static int vdpasim_dma_map(struct vdpa_device *vdpa, unsigned int asid, u64 iova, u64 size, u64 pa, u32 perm, void *opaque) @@ -744,6 +842,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = { .set_group_asid = vdpasim_set_group_asid, .dma_map = vdpasim_dma_map, .dma_unmap = vdpasim_dma_unmap, + .bind_mm = vdpasim_bind_mm, .free = vdpasim_free, }; @@ -776,6 +875,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = { .get_iova_range = vdpasim_get_iova_range, .set_group_asid = vdpasim_set_group_asid, .set_map = vdpasim_set_map, + .bind_mm = vdpasim_bind_mm, .free = vdpasim_free, }; -- 2.38.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
